Analgesics used today in clinical practice suffer either from limited efficacy, limiting side effects or both. The non-steroidal antiinflammatory agents such as aspirin and ibuprofen fail to treat severe pain and cause gastrointestinal side effects. The opiates (morphine, codeine or meperidine) can treat more severe pain, but are subject to addiction liability and cause constipation and respiratory depression.
French Patent 8915407, to Rorer-Rhone Poulenc, discloses the compound: ##STR3## No biological utility is taught.
Eur. Pat. No. 430 771, to Rhone Poulenc, discloses the compound: ##STR4## The biological utility is disclosed as a Substance P antagonist.
Ciba-Giegy has publicly disclosed the compound: ##STR5## However, no biological activity was taught for this compound and its suitability for use as an analgesic is unknown.
U.S. Pat. No. 5,216,018, to Ciganek discloses isoindoles of the formula: ##STR6## wherein R.sup.2 and R.sup.3 are disclosed among many other substituents to be independently phenyl. These compounds are disclosed as useful to treat physiological or drug induced psychosis and as antidyskinetic agents.